OBJECTIVE: Recently, the concept of progressive fibrosing interstitial lung disease (PF-ILD) is wellknown, however, PF-ILD in patients with anti-aminoacyl tRNA synthetase (ARS) antibody-positive interstitial lung disease (ILD) is not well-studied. In this study, we investigated the proportion of PF-ILD in patients with anti-ARS antibody-positive ILD and their backgrounds.

METHODS: We retrospectively analyzed data for patients with anti-ARS antibody-positive ILD who were diagnosed and observed at our hospital between January 1, 2010, and August 31, 2020. The PF-ILD criteria of the Erice ILD Working Group (George PM,et al. Lancet Respir Med. 2020 Sep;8(9):925-34.) were used to determine the PF-ILD.

RESULTS: 97 patients were included; 85 were initiateded on anti-inflammatory drugs (4 of them later in combination with anti-fibrotic drugs), 1 was on anti-fibrotic drugs alone, and 11 were untreated. 21 patients met the criteria of PF-ILD; 3 were insufficiently treated, 17 were intolerant to treatment (due to age, side effects, comorbidities, etc.), and 1 was refractory to treatment.

CONCLUSIONS: There were 21 cases of PF-ILD in patients with anti-ARS antibody-positive ILD, of which only 1 case was refractory to treatment, suggesting that adequate treatment with anti-inflammatory drugs may prevent progression to PF-ILD. Further studies are needed to determine the efficacy of antifibrotic agents and the timing of their introduction in patients who are refractory or intolerant to anti-inflammatory treatment.